Add chromium side flag for enabling/disabling layer squashing.

chrome/browser/about_flags.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/about_flags.h"
 
 #include <algorithm>
 #include <iterator>
 #include <map>
 #include <set>
@@ skipping 395 matching lines @@
   {
     "force-universal-accelerated-composited-scrolling",
      IDS_FLAGS_FORCE_UNIVERSAL_ACCELERATED_OVERFLOW_SCROLL_MODE_NAME,
      IDS_FLAGS_FORCE_UNIVERSAL_ACCELERATED_OVERFLOW_SCROLL_MODE_DESCRIPTION,
      kOsAll,
      ENABLE_DISABLE_VALUE_TYPE(
          switches::kEnableUniversalAcceleratedOverflowScroll,
          switches::kDisableUniversalAcceleratedOverflowScroll)
   },
   {
+    "enable-layer-squashing",
+    IDS_FLAGS_LAYER_SQUASHING_NAME,
+    IDS_FLAGS_LAYER_SQUASHING_DESCRIPTION,
+    kOsAll,
+    ENABLE_DISABLE_VALUE_TYPE(
+        switches::kEnableLayerSquashing,
+        switches::kDisableLayerSquashing)
+  },
+  {
     "present-with-GDI",
     IDS_FLAGS_PRESENT_WITH_GDI_NAME,
     IDS_FLAGS_PRESENT_WITH_GDI_DESCRIPTION,
     kOsWin,
     MULTI_VALUE_TYPE(kGDIPresentChoices)
   },
   {
     "enable-experimental-canvas-features",
     IDS_FLAGS_ENABLE_EXPERIMENTAL_CANVAS_FEATURES_NAME,
     IDS_FLAGS_ENABLE_EXPERIMENTAL_CANVAS_FEATURES_DESCRIPTION,
@@ skipping 1898 matching lines @@
 }
 
 const Experiment* GetExperiments(size_t* count) {
   *count = num_experiments;
   return experiments;
 }
 
 }  // namespace testing
 
 }  // namespace about_flags